patio shrubs suddenly losing leaves

I have a number of shrubs and small fruit bushes that I have been growing for a number of years and are very hardy. This year my pots containing blue berry bush, azaleas, fushia and spirea have suddenly developed what looks like wilted leaves that curl up and then fall. the plants up to know have been doing very well as you can see in the pictures. I had added some bonemeal to them about four weeks ago however it is only in the last two days that the azaleas have had this happen to them. They are in pots in different positions in the garden and not near each other. can any one offer any advice as to what I have done wrong and is this salvageable. thanks.